
We then formulate an optimization problem of \(\mathcal {L}\)  (where \(\mathcal {L}\) , as a weighted integration of the exponential function of \(f\)  and \(g\) , has an analytical expression for Gaussian weights \(q(f,g)\)  [1]}) to determine both the parameters in \(q(f, g)\)  (\(\theta _q\) ) and the hyperparameters (\(\theta \) ):
\(\theta ^*_q, \theta ^* = {\rm {argmax}}_{\theta _q, \theta } \; \mathcal {L}(\theta _q, \theta ).\) 
